Archives May 2013

The youth in any country form an important part of the machinery that shapes the destiny of a country. It is they who may help to bring about a desirable change in society. History has many examples of the contribution of youth towards progress and upliftment of their countries. The youth of India were greatly instrumental in bringing about the independence movement in the country. Gandhiji, Nehruji and other national leaders depended heavily on the youth of India to help achieve the goal of Swaraj. In our own country half of the population constitutes youth and their vast energies and enthusiasm must not go untapped. They should be utilized for social, political, cultural  or economic reconstruction. If their energies are not used, they can go astray, get involved in undesirable and antisocial affairs, thus damaging the very fabric of society. As far as possible they should be encouraged to get more...

"... developed when an enterprising human first daubed mud upon a branch shelter.."   Joseph F. Kennedy, The Art of Natural Building The technique of wattle and daub was first pioneered by human civilizations as early as 6000 B.C.E. as a way of weatherproofing their shelters. In its essence, wattle and daub is a way of filling in the gaps between the structural elements of wooden houses. In a typical Tudor example, oak staves were placed vertically between structural beams and then thin twigs of a flexible hardwood, such as willow or hazel, were woven horizontally between the staves, creating a robust mesh, or "wattle." The wattle was then coated with daub—a mixture of clay or mud and animal dung, strengthened with straw or horsehair. This mixture was pressed onto the wattle by hand. The mud and dung helped the daub adhere to the wattle, and the fiber content prevented more...

The first modems date back to the cold war and 1958, when the North American Air Defense transmitted data over telephone wires to hundreds of radar stations in the United States and Canada. A modem has one essential function, which is to translate the digital language of computers into the analog language of the telephonic system and back again. In 1981 Dennis Hayes (b. 1950) launched the Smart modem (originally named the Hayes Stack Smart modem). This was an automatic modem that for a time led the rapidly emerging personal computer market. Earlier modems were not adaptable to a variety of computers, were expensive to produce, and also were cumbersome to operate, requiring manual connection to telephone lines, The brilliance of the Smart modem lay in its ability to "think for itself" and program itself into the telephone networks* It did this by using its own data language to instruct more...

“I decided that if you could ski on snow, you could ski on water. Everyone... thought I was nuts." Ralph Samuelson, waterskiing pioneer Messing about on the water provides many of life's great pastimes; swimming, fishing, and boating being just a few. In 1922 one more activity was added to this list—waterskiing. Its inventor, Ralph Samuelson (1903- 1977), was already a keen exponent of aquaplaning— the art of being dragged behind a boat on a shaped piece of wood—but he wanted to replicate snow skiing on the water. After .several abortive attempts with barrel staves and snow skis, he build his own skis out of 8-foot (2.5 m) lengths of plank, using his mother's copper kettle to boil the ends of the wood to shape them. When they were ready, his next task was to work out the correct technique for getting himself "launched." For many years, the origins of more...

Before the invention of an effective vaccine for anthrax, the disease was a major agricultural problem and economic burden. Anthrax is a potentially fatal disease that affects animals and humans and is spread via airborne spores. Before it was fully understood, the illness was referred to as "ragpickers' disease" or "woolsorter's disease" because it was mostly caught by people working closely with animal hides. In 1877, the Prussian physician Robert Koch (1843-1910) finally made a link between anthrax infection and a spore-forming bacteria called Bacillus anthracis. In the late nineteenth century, renowned scientist Louis Pasteur (1822-1895) developed a two-dose vaccine for anthrax that he had tested on sheep. However, storage quickly reduced the efficacy of the vaccine, and its effect was sometimes fatal. It was the Australian scientist John McGarvie Smith (1844-1918) and his research collaborator, John Gunn (1860-1910), who eventually developed a safe, single-dose vaccine. Though the the two more...

The belt drive is a vital component of most modern machines. In it, a ring of a flexible material is wound around two or more shafts. As one shaft rotates, the belt moves, causing other shafts to rotate as well. This simple pulley device has long been a versatile and reliable means of transferring power. In 100 B.C.E., while constructing Haterii's Tomb in Rome, workers used a treadmill-powered crane to lift heavy material. This was a historic moment for mechanics. In 1203, French innovators replaced the human workers who had been powering belt-driven technology with a team of donkeys. Introducing animal power was far from the final stop for the belt drive. Water-powered mills used belt drives to harness water power, and Industrial Revolution-era factories employed belt drives, called line shafts, to transfer power throughout the factory. Belt drives are also commonly used in engine designs. Belt drives can be more...

In 1000 B.C.E. it was recorded that King Wen of the Zhou Dynasty, ancient China, designed the first pontoon bridge. The invention was to be incorporated into his elaborate wedding ceremony, allowing the wedding procession to cross the Weihe River. King Wen's design was of a floating bamboo deck structure supported by boatlike pontoons to allow a water crossing. Since their invention, the floating bridges have become much more than just a decorative water crossing—they have become a military weapon. One of the earliest recorded pontoon bridges to be used in combat was built in 974 C.E. by the Song Army of ancient China, who constructed it in fewer than three days. However, such bridges take a lot less time to destroy or dismantle—a necessary practice to prevent the enemy from following, King Wen's design is still being used by the military to this day. In 2003 the U.S. Army's more...

"The vacuum cup may save many mothers from difficult and dangerous forceps deliveries." Time magazine (1960) The ventouse is a vacuum device that was developed to assist in the delivery of a baby when labor is not progressing well. It was developed in Sweden by obstetrician Tage Malmstrom (1911-1995) as an alternative to forceps. Malmstrom had the idea of using a bicycle pump to create the vacuum pressure. A bowl-like apparatus is attached to the baby's head in the birth canal. Air between the baby's head and the apparatus is then sucked out to create a vacuum. The doctor, who controls the amount of suction applied, synchronizes the pressure applied with the mother's contractions, enabling the baby to be delivered. The suction cups can be either flexible (soft plastic or-silicon) or rigid (hard plastic or metal). The ventouse may cause less maternal trauma than forceps, but is thought to be more...

It is very important to be cautious about health. I take great care to see that I remain healthy. For that I read books      on health care and never miss a television programme where health care is spoken of by doctors. Health can be maintained by eating good nutritious food. This includes eggs, milk, pulses, fruits, etc. As I am a vegetarian I try to eat a lot of butter, cheese and drink a lot of milk. I supplement my diet with vitamins and avoid medication. In youth this temptation is all the more stronger. It is too much, therefore, to expect boys to attend wholeheartedly to their lessons when a number of attractive girls are sitting by their side in the class room, Again, there is a real danger that the free inter-mixing of the sexes at the age of puberty may lead to sexual misconduct. Boys more...

LCDs (liquid crystal displays) are used in televisions, laptop computers, and many portable electronic devices. The properties of liquid crystals were first discovered in 1888 by Friedrich Reinitzer. He was measuring the melting point of a cholesterol-based substance and noticed that it had two melting points: it melted at 293°F (145°C) to give a cloudy, gluelike liquid, then again at 352°F (178°C) to give a clear liquid. Otto Lehmann, an expert in crystal optics, studied these phases and found that the cloudy liquid had similar properties to the solid crystal. In the solid crystal, the molecules are lined up neatly and in parallel. In the cloudy liquid, the molecules can move around. However they tend to line up like in the solid crystal, reflecting light to appear cloudy. Lehmann named the liquid fliessende Kristalle, or liquid crystal. In 1968 George Heilmeier (b. 1936) led a group at the Radio Corporation more...